/**
* @author AlbertDarren
* @contact 2563491540@qq.com
*/
#include <iostream>

using namespace std;

int main_19()
{
    int piece;
    scanf("%d",&piece);
    double money=piece*95;
    if (money>=300)
    {
        money*=0.85;
    }
    printf("%.2lf",money);
	return 0;
}
